Apparatus for forming a hinge surface on a last block



Dec. 26, 1950 L. E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Filed Feb. 14, 1945 8 Sheets-Sheet 1 [n ven tors Laurence E YBpham Garrett PS Cross By T/zez'r Attorney Dec. 26, 1950 L. E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Filed Feb. 14, 1945 a Sheets-Sheet 2 In ven to rs Laurence E Tpham Garrett P 8 Grass By their Attorney Dec. 26, 1950 L. E. TOPHAM ET Al. 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Filed Feb. 14, 1945 s Sheets-Sheet 5 Inventors Laurence E 722 ham Garrett PS was .23 their Attorney 1950 L. E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Filed Feb. 14, 1945 8 Sheets-Sheet 4 219 as 252 Y 254 159 Inventors Laurence E YBp/zam 34 Garrett 7? LS: Gross .By their Attorney 6, 1950' L. E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Fil ed Feb. 14, 1945 8 Sheets-Sheet 5 hvenfor's Laurence E. YBpham Garrett P S Gross By theirAttorney yam 95M Dec. 26, 1950 L. E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK Filed Feb. 14, 1945 8 Sheets-Sheet 7 in van tors Lau'renoe E YEP/mm Garrett P 5 Gross By heir-Altar Dec. 26, 1950 E. TOPHAM ET AL 2,535,465

APPARATUS FOR FORMING A HINGE SURFACE ON A LAST BLOCK 8 Sheets-Sheet 8 Filed Feb. 14, 1945 v w; w: m: 2 a 1 X a \l l Inventors Laurencef. Topham GarreIftPSCross By their/1 Patented Dec. 26, 1950 APPARATUS FOR- FORMING A HINGE SURFACE ON A LAST BLOCK Laurence E. Topham, Wenham, and Garrett P. S. Cross, Beverly, Mass, assignors to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application February 14, 1945, Serial No. 577,750

2 Claims.

The purpose of this invention is to provide improved apparatus for performing woodworking operations on last blocks to prepare them for turning in a copying lathe. The preparatory operations are predicated upon two-part lasts of the type in which a forepart and a heel part are provided with cooperative hinge-forming portions that permit relative collapsing movement of the parts.

In a last of the type under consideration the cylindrical hinge knuckle may be formed on the forepart or onthe heel part, according to the preference of the last manufacturers or their customers, shoe manufacturers, but so far as the principles of this invention are concerned the choice is of little or no moment. Accordingly, to avoid unduly limiting the claims on this score, the expression cylindrical hinge surface or other expression of similar import is to be understood as indicating either a hinge knuckle or a counterpartal socket for receiving such a knuckle. Moreover, while the drawings and the description disclose the subject matter only in its application to the production of foreparts, some, if not all, of the illustrated apparatus may be used to prepare heel part blocks for turning in a copying lathe.

The primary controlling factor involved in the invention is obtained by boring a master hole widthwise through a rough block near its hinge end. The block may be intended for a forepart or a heel part, and the hole may be ultimately occupied by an anchoring pin of a connecting link, but the ultimate use of this hole is not essential unless a connecting link of standardized dimensions i to be installed. Be that as it may, no precision is required in locating this hole, provided its location is within the limits afforded by the quantity of surplus wood in the block. Once this hole is bored it may be utilized as a constant from which to gauge, directly or. indirectly, the relations of the surfaces to be generated in successive operations including the turning operation in a copying lathe.

The first duty of the aforesaid master hole is to establish a predetermined relation between the block and a jig in which three or more successive operations may be performed before the block is released therefrom to be transferred to a copying lathe. The jig includes a registering means adapted to project into the master hole in the block and by its engagement therewith to locate the axis of the hole positively in parallel relation to a path of rectilinear movement by which the hinge end of the block and a formed cutter may be relatively traversed to generate a cylindrical hinge surface (knuckle or recess) and a stop shoulder or abutment surface below it. Such use of the hole to locate the block with respect to the formed cutter insures not only the parallel relation above mentioned but also a predetermined correlation of the hole and all the surfaces to be generated by the formed cutter.

Referring to the drawings:

Fig. l is a top plan view of an apparatus equipped to generate the joint surface, cut a heightwise kerf and bore a center hole in a block in accordance with this invention;

Fig. 2 is an elevation thereof partly in section and including a forepart block set up and secured in the registering means;

Fig. 3 is a sectional view of an adjustable stop forming a part of the registering means;

Fig. 4 is an elevation of the kerfing unit included in Fig. 1;

Fig. 5 is an elevation of a forepart block partly in section and embodying the results obtainable from partial use of the working units included in Fig. 1;

Fig. 5A illustrates how the kerf represented in Fig, 5 could be extended heightwise with the same working units;

Fig. 6 is an elevation of the hinge end of the block prepared as shown in Fig. 5;

Fig. 7 is a top plan view of interlockin controls for the work carriage and the kerfing unit;

Fig. 8 is an elevation of the kerfing unit, partly in section, the direction of view being the reverse of Fig. 4;

Figs. 9, 12 and 14 are sectional elevations of a control in successive positions corresponding to Figs. 8, 1'1 and 13 respectively;

Fig. 10 is a sectional elevation of trip mechanism appearing in another relation in Fig. 8;

Fig. 11 represents the structure of Fig. 8 as when the kerf cutter is fully advanced (to the left) and cutting the deepest part of a kerf;

Fig. 13 represents the same structure as when the kerf cutter is retracted to an intermediate position;

. Fig. 16 represents a group of locking elements otherwise related in Fig. 7;

Fig. 16 represents a train of controls by which the carriage of the kerfing unit is locked when the cradle thereof is rocked;

Fig. 17 is a plan view of a portion of the centor-boring unit;

Fig. 18 is an elevation, partly in section, of the assemblage shown in Fig. 17;

Fig. 19 is a diagram representing the relation between the cylindrical hinge formation at one end of a block and a group of alternative locations for a center hole at the opposite end, any

one of which may be selected to determine a 3 ing the heightwise pitch of the turning axis in a block, this being the pitch that determines the quantity of bottom spring in a completed last;

Fig. 21 is a similar schematic view indicating the relation involved in establishing the "widthwise pitch of the turning axis, this being the pitch that determines the swing, or lack of swing, in the completed last;

Fig. 22 illustrates in a plan view howa prepared forepart block and a forepart model may be set up in a copying lathe ifOI' .a turning opera-. tion according to the principles of this invention;

Fig. 23 is an end elevation of a driving element of the lathe designed to engage the hinge formation of the forepart block; and

Fig. 24 is an elevation of a completed last of a type with which the invention is concerned, the dotted outline of the forepart block being superposed thereon to indicate the factors involved in establishing the spring of the last.

Referring to Fig. 5, which represents a rough hewn forepart block 48 cut to a desired length, the invention is predicated upon boring a master hole ie widthwise through the block near its hinge end, generating a joint surface at that end including a cylindrical hinge surface i 1, and a stop shoulder I56 below it, cutting a heightwise kerf 25 i intersecting the hinge surface and lying in a plane at right angles to the axis H55 (dot) thereof, boring a center hole 1% in the toe end, sawing 01f the surplus wood above the hinge surface, and turning a forepart on an axis 258 intersecting the axis 155 and the center hole 652. If a heel part block were to be processed in like manner the only essential difference required would be in the hinge surface where a mating curvature would be necessary.

The intermediate operations .above specified, if performed at all, :need not be performed in the order of their recital, but the boring of the master hole 39 must be the first operation and the turning operation must be the last to derive all the benefits of precision and style variation .contemplated. The order of recital is the one preferred and the description will proceed accordingly.

No special apparatus is shown or required to bore the hole 55, since .a. common drill press will do. A block 38 so bored is first located in registering means as shown in Fig. 2 in which two coaxial trunnions ll, maintained on a fixed axis, project into the ends of the hole 39 to fix the location of the axis of the hole. The toe portion of the block rests on a vertically adjustable bolster screw 68 and is tightly clamped against it by means to be described. The screw is provided with a lock nut it}. The operator will know whether the new product is to have much or little spring and will adjust the screw accordingly, but no precision is required here. The toe end of the block may thus be located at various levels while the hole 59 remains at a constant level established by the trunnions M (Fig. 20).

Again referring to Fig. 2, the left-hand trunnion is affixed to a stand 38 while the right-hand trunnion is afiixed to a bracket is mounted on a carriage 36 of which the stand 38 is a part. The bracket is adjustable toward and from the stand in lines parallel with the trunnions, and may be set to clamp the block widthwise against the stand by operating a lever 50 also mounted 4 on the carriage 35 (Fig. 1) and connected thereto by a fulcrum stud 52. An arm 62 of this lever is connected to the bracket ill by a lint: 5. A pawl 5d carried by the lever cooperates with ratchet teeth 56 to maintain the clamping pressure. The teeth are formed on a plate 58 afiixed to the carriage by the stud 52 and a screw in a boss 60. The "bracket 48 is constrained to rectilinear movement by a rod it and a track 62. The latter is afiixed to the carriage but the rod is afiixed to the bracket and slides in bearings 4.4 in the carriage.

To provide for clamping the block 33 against the screw 68 the carriage 3t is provided with two upstanding arms 76 and (Fig. 2) and an adjustable clamping bar 12 bridging the space between them. A pivot pin 14 connects the bar and the arm FIG which has a series of holes to receive the pin at various levels. A handle 84 is located between a pair of confronting cheeks 8-8 of the bar and is connected to them by a pivot pin 86 about which it may swing to retract a gang of :pawls 98 from ratchet teeth 94. For this purpose a single tooth is formed-on the handle and each pawl has a notch to receive it. The paw-ls are all mounted on a common pivot pin 96 in the cheeks and they are of different lengths to break down the spacing of the teeth 94 into relatively small increments of adjustment. Spring-pressed pins J99, one in .each pawl, bear against an abutment I 32 and their reaction presses the pawls against the teeth 95. A portion of the handle 81% normally rests against a stop I06, but when the handle is lifted its tooth Ifi i retracts the pawls from the teeth 84. Then, the handle is effective to raise the bar :52 to a stop 22 against which .a tension spring H6 will hold it, the spring and the bar being connected 'by an eye .1 i8 while the spring and the carriage are connected by a hook I320. The block 52 on which the teeth 94 are formed is afiixed to the arm 98, :both being arranged to be straddled by the cheeks 88.

The bar E2 carries .a clamping plunger I98, an eccentric 1L2 for operating it, and a handle lit for turning the shaft to which the eccentric is aiiixed. When the bar is brought down across a work block 18,, it is arrested and latched .at a suitable l vel when the contact piece NE; of the plunger 1133 engages the block. Then, the clamping pressure maybe applied by operating the eccentric I I2 to depress the plunger K 8.

When the work block has been registered and secured to the carriage 36, the operator, standingjat the left endof themachine (Figs. 1 and 2), will shift the carriage from left to right. The carriage is provided with .a handle I24 for this purpose, and with arms 126 for carryin it. The carriage is constrained toa rectilinear path parallel with the axis X (Fig. 21) of the master hole 49 as fixed by the registering trunnions M. This shifting of the carriage causes the hinge end of .the work block 48 to traverse a cutter head by which the surfaces l54, I 56 and -i58 (Fig. 20) are generated in a fixed standardized relation to the hole 49.

The cutter head rotates about a fixed axis I ll its shaft 146 being journaled in bearings in the bed :32 and base '30 of the machine. An electric motor (not shown) may be used to drive the shaft. The cutter head comprises two similar cutting blades I49 (Figs. 1 and 2) adjustably secured in dovetail holders including a clamping collar .144. Each blade has two straight cutting edges connected by :a semicircular cutting edge I42 designed to generate the cylindrical hinge surface I54.

In Fig. 20 the profile of revolution of the cutter is represented by broken lines, the axis of rotation is indicated by line MI, and the axis of the generated hinge surface I54 is indicated at I55 (dot). In Fig. 21 (plan View) the line I43 represents the path of revolution of the centers of curvature of the semicircular cutting edges I42, while the line I 55 represents the axis of the hinge surface I54. In this diagram it should be observed that the line I55 is tangential to the path of the centers of curvature of the edges I42. This line will be referred to again in connection with the step of boring a center hole 462 in the work block.

The carriage 36 slides on straight tracks 34 secured to the bed 32 and its range of traverse is long enough to carry the work block past and beyond the formed cutter and finally into register with a kerfing unit and a boring unit where it is arrested byya surface I60 of a stop I36 affixed to the bed by bolts I38. A rod I34 extending through a portion of the carriage is arranged to cooperate with the stop I36. A screw-thread on one end of this rod engages an internal thread in the carriage, and the rod may be rotated to adjust it endwise. The other end of the rod (Fig. 3) and a short portion of its length are of square section and this portion is provided with an internally squared sleeve I90 by which it may be rotated and locked to the carriage. This sleeve is normally held against a cotter pin I9! by a compression spring I84 but may be slid along the square portion to release it from a fixed detent I99 that normally projects into a depression in a portion I 88 of the sleeve. When a circumferential groove I88 in the sleeve is in register with the detent the sleeve and the rod I34 may be rotated, but otherwise the portion I88 and the detent are interlocked.

The rod has a bearing in a bushing I82 secured in the carriage 36. The bushing supports a housing I82 in which a rotatable dial I0! cooperates with a window to display symbols (not illustrated). The symbols may indicate increments of adjustment of the rod I34. The dial is carried by a gear I04 to which rotation is transmitted by an intermediate gear I96 from a gear I86 on the sleeve I00.

The carriage 36 is provided with a guard I30 adjacent to the handle I24 and arranged to mask the formed cutter when the handle is near the latter. The cutter is otherwise masked by a stationary dust hood I48 through which dust and chips may be drawn by air suction in a dusttrunk 550 (Fig. 1).

The carriage also carries a resilient anti-recoil device arranged to take effect when the rod I34 is near or touching the stop I36. This device (Fig. 2) comprises an arm I98, a pivot 200 connecting the arm and the carriage, a roller 202 carried by the arm, and a tension spring 204 connecting the arm and the carriage. Through all but a short portion of the traverse of the carriage the roller rolls on the upper surface of the bed 32 with no appreciable effect, but the traverse takes it beyond the right-hand edge of the bed, whereupon it rolls down on the end face of the bed until the arm I08 is about vertical and at right angles to the line of pull of the string. At this stage the carriage is arrested by the stop $36, but the spring then tends to pull the carriage toward the stop.

The kerfing unit (Figs. 1 and 4) comprises a chain saw 244, an electric motor 246 for driving the saw, a cradle 236 in which the motor casing is fastened, a carriage MB in which the cradle is suspended by horizontal trunnions 234, and a frame 206 with which the carriage has sliding connection provided by a rod 2I2 and a grooved track 2 I 8. The path of the carriage 2 I 6 is straight but inclined, and it extends at right angles to that of the Work carriage 36. The frame 206 is afiixed to the bed 32 and is provided with bearings 208 and 2I0 in which the rod 2I2 may slide. The track 2 I8 is a part of the frame 206, and a margin of the carriage 2I6 slides in it. The rectilinear traverse of this carriage provides for cutting a deep kerf 254 (Fig. 5) that intersects the master hole 49 and is of a size to accommodate one end portion of a connectin link 255 (Fig. 24), while the suspension of the cradle on the trunnions 234 provides for rocking the saw to extend the kerf heightwise. One example of hardware that requires heightwise extension of kerfs is disclosed in United States Letters Patent No. 2,085,148, granted June 29, 1937, on application of G. P. S. Cross.

The chain saw runs on a driving sprocket 250 and an idle roll 242, the former being afiixed to the shaft 248 of the motor 246. The idle roll is rotatably mounted in a slotted arm 240 adjusta bly affixed to a portion 238 of the cradle by a clamping screw 239.

In Figs. 1, 4 and 8 the carriage 2I6 is retracted and held against advancement by a shoulder 3I4 of a latching arm 308 on which a block 338 is caught. This block is fastened to the carriage by a screw 340 andthe carriage is fastened to the guiding rod 2 I2 by a pin 2I4. The tendency of the carriage to slide down grade is opposed in some degree by a tension spring 390 but is not wholly counterbalanced thereby. The latching arm 308 is normally held up by a tension spring 320 connecting the arm 3I8 and a trigger 322. The latching arm and the trigger are both con nected to the frame 206, one by a pivot pin 3I0 and the other by a pivot pin 324, and they take successive positions shown in Figs. 8, 10, 11 and 13.

To use a kerfing unit the operator first retracts the carriage 2I6 very slightly from a primary retracted position (Fig. 8) by depressing a handle 230 affixed to a rockshaft 222 (Fig. 1) to which a gear 220 is also affixed. The teeth of this gear engage teeth 228 formed on the rod 2I2 to which the carriage is pinned. This first movement of the carriage causes the block 338 to ride a cam surface 342 on the arm 308 and thereby depress the tip 336 of the latter below a shoulder 328 of the trigger 322, whereupon the arm 308 will be caught by the trigger 322 as in Fig. 10. Now, since the carriage is released from the arm 308, the operator may raise the handle 230 to feed the carriage down grade, thereby causing the chain saw 244 to cut a kerf in the work block of the form indicated by the recess 254 (Fig. 5). The depth of this recess may be regulated by adjusting a stop 260 in the path of the carriage. The stop straddles the rod H2 and is secured to the bearing 2I0 (Fig. 7) by a set screw 26I.

Before the carriage is arrested by the stop 268 its block 338 engages the tip 330 of the trigger 322 and displaces the latter to trip the arm 308 (Fig. 11), whereupon the spring 320 raises the arm 388 to its latching position where it is arrested by a portion 3I2 of the frame 206 in the path of a pin 326 carried by the arm 3I8. Now, if the kerf in the work block does not need extending heightwise, the operator may return. the handle 230; to its initial position. and: the saw carriage likewise, but, assuming that some heightwise extension of the kerf is needed for clearance of some types of hardware, he may in terrupt the return movement of the handle at an intermediate position where the block 338, after riding over a ratchet tooth 334 on the 358, may settle back against the abrupt side of this tooth as shown in Fig. 13. The saw car-- riage may dwell. at this position while the op-- erator rocks the cradle 236 on its trunnions 234.. Thereafter, the final stage of return movement or the carriage will restore the block 338- to en.- gagement with. theshoulder 3 [4 of the arm 3518'.

The saw carriage and the cradle are controlled by interlocking means, one e-fiect of which isto prevent rocking the cradle except when the carriage occupies a predetermined position (Fig.

13), the other to prevent shifting the carriage away from that position except when the cradle occupies a predetermined angular position (Figs. 4', 8, l1 and 13). According to Fig. 16, the carriage is locked and the cradle unlocked. A rod 366 ailixed to the cradle provides for rocking it. One end of the rod is secured in a boss 368 of the cradle by a binder 310. Rocking motion is derived from a crank pinv 35.2 carried by a disk 3. The connections for utilizing the motion of the crank pin include a link 350, a lever 356 a pivot pin 3'54, a sleeve 38.4 slidable on the rod 366 and a pivot pin 362:. A portion 360 of the frame 266' supports a fulcrum pin 358 on which. the lever 35.6 rocks. The crank disk. 344 is affixed to an operating shaft 346 (Fig. 1) provided with a hand wheel 348. The parts: are so coordinated that when the crank pin stands at half stroke (Figs. 4 and 8) the rod 366 is parallel with the path of the saw carriage. Consequently, the rod may slide to and fro through the sleeve 364 Without rocking. the cradle when the carriage is being shifted.

A V-sh aped notch 334 in the. periphery of the disk 344' is adapted to receive one end of a horizontal locking bolt 382 arranged to slide endwise in hearings in the framev 206. The" axes. of this bolt and the shaft 222 are normal to each other. This end of the. bolt is rounded to be cammed out of the notch by either wall thereof, but is normally maintained in the notch by a compression spring 386- and a collar 3 88 fas t'ened to the bolt. These. parts normally maintain the parallel. relation of the rods. 366 and 2152. The other end of the bolt 382 is arranged to enter a radial bore or socket 380 in a sleeve 37% clamped to the shaft: 222 by a binder 318 (Figs. 7 and 9-) which provides for angular adjustment of the sleeve; The adjustment pictured in the drawings enables the bolt to enter the socket 38 only when the. saw carriage stands. in the intermediate position represented in Fig. 13. If, therefore, the saw carriage is not in that position, the sleeve 3T6 will positively maintain interlocked relation of the bolt and the disk 344 to prevent rocking the cradle. On the other hand, when the socket 388 is in register with the bolt (Fig. 14) the disk 344 may be turned in either direction by the hand wheel 348. The disk will shoot the bolt into the socket incidentally torccking the cradle, and the saw carriage will be locked against movement upgrade as well as down grade until the cradle is returned to its initial angular position. Then, the bolt under the influence of the spring 386 will release the saw carriage and lock the cradle. The operat- 8 ing handle 230 may then be moved to complete the return of the saw carriage.

If a kerf of the shape shown in Fig. 5 will sufiice, the cradle 23G need not be rocked because the traverse of the; saw carriage 2I6' will produce that shape. On the other hand, if the kerf requires heightwise elongation above or below its primary limits as shown in Fig. 5A,. one complete revolution of the hand wheel 3 1-8 (Fig. 1) will produce both extensions. The: extension. 256 may be produced by turning the crank pin 352 (Fig. 1.6) to top center, but the extension 252 is the result of turning it to bottom. center. The. operator may stop short of either or both 4- limits of extension, since the direction and; extent of rotation of the hand wheel are both subject to the will of the. operator. In. any event, the spring 386' will shoot the bolt 382 to the right whenever the V-shaped notch 384 is returned to its initial position, thereby unlocking thesaw carriage H6 and centering the cradle 238..

In addition to the reciprocal controls involving the saw carriage and the cradle, the invention provides means controllably related to the saw carriage for locking and unlocking the: work carriage 35 when the latter is in register with the kerfing unit. For this purpose, a bar I52 (Figs. 1, 7 and 15) is affixed to the work carriage and. is provided with a series of locking teeth arranged to be engaged by locking. pawlsv 262. and 264. These pawls are mounted in a block 218 seated on the bed 32 and anchored thereto by screws 212. A pivot pin 263 connects the pawl 262 and the block while a pivot pin 2-14 connects the pawl 264 and the block. Anarm 27-5 of the pawl 2G2 and an arm 21-3 of the pawl 264 are arranged to be engaged by the head 216 of a ram- The other end of the ram and an 234 (Fig. 8) are connected by a pin 28 2. This arm is loosely mounted on the shaft 222 and its hub has a segmental recess that provides a shoulder 384, the angular extent of the recess being a little more than The recess is occupied by a pin 302 affixed to a collar 298, the latter being afiixed tothe rockshaft 222 by a screw 303' (Fig; '7)

The parts just described operate as follows: when the handle 230 occupies its initial position (Fig. 8') the pin 3G2 engages the shoulder 3Mand thereby causes the ram 278 to restrain the pawls 2'62 and 264 out of the path of the teeth on. the bar E52, but when the handle is raised to advance the saw carriage the pin 392 leaves the shoulder 334 and travels toward the other end of the recess. Then the ram is retracted from the pawls by a compression spring 295- interposed between a fixture 289 and a collar 294. The pawls, now unrestrained by the ram, are moved to their locking positions (Fig. 15-) by followers 286 and 288 and compression springs 259 and 292 located in sockets in the block 210. The pin 302 may travel in the recessinthe arm 284 without further effect until the handle 238 returns to its initial position, when it again engages the shoulder 3 04 and swings the arm to retract the pawls from theirlockingpositions.

The boring unit hereinbefore mentioned is arranged to bore a center hole 462 in the toe end of a block 48 while the latter remains at the inertcutting station. This unit ma be adjusted angularly about two'- fixed axes that intersect eachother at right-angles, one of them coinciding with the axis l55 of the cylindrical hinge surface generated by the formed cutter (Fig- 2-1) and the other being represented by a dot 46L Their point of intersection is midway between the cheeks of the kerf cut by the chain saw, or, as related to the saw itself, midway between the planes of the sides of the saw.

The boring unit comprises a drill 392 (Fig. 1), a drill chuck 394 carried by a rotary spindle, a bearing sleeve in which the spindle is journaled, an electric motor 398, pulleys 402 and 404 afllxed to the spindle and the motor shaft, respectively, and a transmission belt 400 connecting the pulleys. These elements are all mounted on a frame 436 which includes a boss 396 in which the hearing sleeve of the drill spindle may slide endwise to advance and retract the drill, all according to a well-known commercial design. The bearing sleeve has rack teeth engaging a pinion 406 (Fig. 17) to be rotated in one direction by pulling a flexible cable to which a pull knob 40-8 is attached, the cable being wound around a spool on the shaft of the pinion. A coiled spring attached to the pinion shaft normally retracts the drill and winds the cable on the spool.

The frame 436 that guides the boring unit has two parallel bores occupied by arms 432 and 434 of an adjustable supporting frame 430. The frame 436 may be adjusted lengthwise of the arms and secured to the arm 432 by a clamping screw 438. This detail provides for locating the drill 392 according to the length of a work block 48. The supporting frame 430 is angularlyadjustable about the horizontal axis 155 and is superposed upon a frame comprising a base plate 416 and an upright 426 (Figs. 17 and 18). The latter frame is angularly adjustable about a vertical axisthat intersects the aforesaid horizontal axis at the point indicated by the dot 461 in Fig. 21. Moreover, the axis of, the drill 392 also intersects the same point.

The frame 416, 426 is seated on a bolster plate 420 affixed to the bed 32. Arcuate tongue-andgroove connection is provided by a tongue member 419 fastened to the plate 420 and a groove 418 in the plate 416. The center of their are is the vertical axis indicated by the dot 461. The tongue member has a series of indexing holes 424 any one of which may receive an indexing pin 422 carried by the frame 416, 426. One of these holes is located. to establish right-angular relation of the drill and the axis 155 (Fig. 21) while the others provide for angular increments of 2 each to modify the swing of a forepart product with respect to the axis of its cylindrical hinge surface.

The frames 426 and 430 have an arcuate tongue-and-groove connection the radial center of which is the horizontal axis indicated by the dot 155 (Fig. This connection includes an arcuate bearing portion 428 of the upright 426, arcuate guiding flanges on the frame 430, and a clamping plate 458 overlapping the flanges. A screw 454 having a handle 460 is arranged to tighten the plate against the flanges. Provisions for adjusting the frame 430 include gear teeth 444 on the portion 428, a pinion 440, a shaft 442 journaled in a portion 448 of the frame 430, and a handle 446 for turning the pinion. An indexing pin 452 carried by the handle is adapted to enter any one of a series of indexing holes 450 formed in the portion 448, the hole midway of the series corresponding to the level at which the drill should bore a center hole 462 (Fig. 24) to produce the same toe spring in a forepart at zero grade as the toe spring of the model from which the forepart is to be turned. A slot 456 in the frame 430 provides clearance 10 for the shank of the screw 454 as the boring unit is adjusted to regulate the toe spring.

When the frame 416, 426 occupies its midposition of adjustment the center hole 462 bored by the drill will coincide with the median vertical plane of the chain saw (Fig. 21), and the ultimate effect of its location will be to produce the same swing in the forepart as that in the model from which the forepart is to be turned. A different swing may be produced by shifting the drill sidewise. In Fig. 21 the broken lines 258 represent two variants of the axis of the drill, both diverging from the point where the axis intersects the axis 461 and both corresponding to adjustments of the frame 416, 426. In Fig. 20 the broken lines 258 also represent two variants of the axis of the drill, both corresponding to adjustments of the frame 436. Whichever boring axis 258 is selected ultimately becomes the turning axis of the forepart block. The bolster screw 68 will usually be set higher for a high boring axis than for a low boring axis, but the critical relation with regard to the ultimate spring and swing of the last will be the angular relation between the plane of the stop face 156 and the selected boring axis 258. Fig. 19 illustrates twenty-five different 10- cations at which a center hole 462 may be bored, the central location being the only one corresponding to an exact duplication of both spring and swing of a model. The circular outline of this figure is merely a symbolic representation of a work block 48 in end elevation.

Fig. 13 includes adjustable means for arresting the boring stroke of the drill 392 to limit the depth of the bore 462. .For this purpose a stop nut 410 is carried by a screw 412 and ar ranged to coact with a stop shoulder 409 on the boss 395 of the frame 435. The screw 412 is affixed to a collar 414 and the latter is tightly clamped to the axially movable bearing sleeve in which the drill spindle is ,iournaled. The screw extends loosely through the shoulder 409 and is movable relatively thereto.

Assuming that a forepart block 48 has been provided with a joint surface, a kerf for a connecting link, and a center hole 462, the operator may return the work carriage 36 to its initial position (Figs. 1 and 2) and release the block by manipulating the handles 84 and 53 as here inbefore explained. The next step will be to saw off the surplus wood above the hinge surface 154 (Fig. 5) with a cut in a plane indicated by the line 159. No precision is required for this operation, but the out should terminate at the top of the hinge surface. A simple jig (not shown) may be used for this operation. The block will then be in the condition represented in Fig. 22 and ready for turning in a copying lathe.

Fig. 22 also includes some of the elements of a lathe assemblage, this type of lathe being more fully shown and. described in United States Letters Patent No. 2,072,228, granted March 2, 1937, on application of L. E. Topham et al. The elements herein illustrated include a forepart model 500, a model wheel 501, a turning center 502 for the toe of the model, a face plate 503 for supporting and rotating the model, a rotary cutter 504, a turning center 505 for the toe of the block 48, a chuck 506 for supporting and driving the block, a face plate 501 by which the chuck is carried, a turning spindle 508 to which both face plates are affixed, and a gear 509 by which rotation is transmitted to the spindle from other gears "not shown. The two turning centers and the spindle 508 are all mounted in a swing frame, not shown, and have a common turning axis. 7

The chuck 505, of which a plurality of interchangeable variants may be provided, is, in one sense, an adapter. It is provided with holes 5H1 for attaching screws to be screwed into the face plate 501. The chuck is designed not only to rotate the block 43 but also to establish and maintain correlation of the block and the model. It is provided with a semicylindrical groove the concave surface 5H of which is a counterpart of the convex hinge surface I54 of the block except that the angular extent of the concave surface is a little less than that of the convex surface to provide a margin of clearance. If the hinge surface of the block were concave the chuck selected for use therewith would have a counter-partal convex surface instead of a concave surface. A fin 512 set into the chuck and intersecting its counterpartal surface on the rotational axis is adapted to occupy the kerf in the hinge portion of the block and thereby establish sidewise register of that end a I represented by the five horizontal rows of hole locations indicated in Fig. .19.

.The five vertical rows of locations represent different angles of swing. If the swing of the new forep'art is to be the same as that of the model. the operator will select a chuck 506 in which the axis of the counterpartal surface 5!] lies at right angles to the turn-'ng axis, but if the swing of the new io-repart is to be difierent from that of the model, he will select a chuck in which the axis of the counterpartal surface is skewed in accordance with the angle of skewing that was selected for the drill 392 (Fig. 21.) and the hole 462 drilled thereby. Each chuck maybe attached to its face plate in ether of two angular relations 180 apart, one of which will absorb right swing and the other left swing of the hinge portion of the block. Therefore, a total of three chucks will fulfill the requirements of twenty-five different turning axes of work blocks, including the normal axis of zero deviation from model spring and model swing.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. An apparatustor operating on a last-part block, the apparatus comprising relatively movable units, one a cutting unit and the other a work-holder, and guiding means by which their relative feeding movement is constrained to a straight path, the work-holder including cooperative coaxial trunnions the axis of which is parallel with said path, said trunnions being arranged to project into the ends of a hole extending widthwise through a work block, and the cutting unit having a rotary formed cutter for gencrating a cylindrical hinge surface on the block in consequence of relative feeding movement of the units along said path.

2. An apparatus for operating on a last-part block, the apparatus comprising relatively movable units, one a cutting unit and the other a work-holder, and guiding means by which their relative feedng movement is constrained to a straight path, the work-holder including clamping means and cooperative coaxial trunnions the axis of which is parallel with said path, the trunnions being arranged to project into the ends of a hole extending widthwse through a work block and the clamping means bein arranged to engage the top and bottom of the block, the cutting nnit having a rotary formed cutter ior generat ing a. cylindrical hinge surface on the block in consequence of relative feeding movement of the units along said path.

LAURENCE E. TOPHAM. GARRETT P. S. CROSS.

REFERENCES CITED UNITED STATES PATENTS Numher Name Date 379,930 .Branton .Mar. 27, 1888 458,613 Brown Sept. 1, 1891 491,493 Rebhun Feb. '7, 1893 541,158 Fitz June 18, 1895 1,054,073 Zimmermann Feb. 25, 1913 1,104,743 Ballard July 21, 1914 1,427,805 Hadaw-ayet a1 Sept. 5, 1922 1,588,703 Clausfng June 15, 1926 1,630,173 Dumont May 24, 1927 1,761,663 Gray June 3, 1930 1,952,270 March et al Mar. 2'7, 1934 1,969,740 Fitzpatrick Aug. 14, 1934 .'2,030,141 Fitzpatrick Feb. 11, 1936 2,314,660 Peterman Mar. 23, 1943 2336,049 Topham Dec. '7, 1943 2,357,230 Shade Aug. 29, 1944 FOREIGN PATENTS Number Country Date 505,326 France May 3, 1920 146,629 Switzerland July 1, 1931 

